WO2008050939A1

WO2008050939A1 - Button type character input device and input method

Info

Publication number: WO2008050939A1
Application number: PCT/KR2007/001389
Authority: WO
Inventors: Hyung Gi Kim
Original assignee: Mobiis Co., Ltd.
Priority date: 2006-10-23
Filing date: 2007-03-22
Publication date: 2008-05-02

Abstract

The present invention relates to a button-type character input device and character input method, and more particularly, to such a button-type character input device and character input method, in which a character to be input is assigned to a button consisting of a switch, etc., and a character is input or corrected conveniently through the depression of buttons and the shift of the button-depressed position. The button-type character input device a first region comprises: a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons; and a character display section for displaying the current character, wherein the input-processing section designates as a current character any one of characters assigned to a second button according to the depression of the second button.

Description

BUTTON TYPE CHARACTER INPUT DEVICE AND INPUT

METHOD

Technical Field

[1] The present invention relates to a button-type character input device and character input method, and more particularly, to such a button-type character input device and character input method, in which a character to be input is assigned to a button consisting of a switch, etc., and a character is input or corrected conveniently through the depression of buttons and the shift of the button-depressed position, which was filed with Korean Intellectual Property Office (KIPO) as Korean Patent Application No. 2006-105535 and was registered as Korean Patent Registration No. 684647. Background Art

[2] In general, it is well known that as shown in FIG. 1, buttons including switches are arranged on a keypad of a cellular phone and two to three characters are assigned to each button so that a desired character is selectively input depending on the number of depressions of buttons.

[3] However, in case of such a keypad of the cellular phone, since a number of buttons are densely arranged on the keypad, there frequently occur mistaken inputs of characters, so that a user suffers from an inconvenience of having to depress a cancel/ clear button and then re-enter a character it is wished to input so as to correct this input mistake.

[4] To address and solve the above problem, the present applicant has filed a Korean

Patent Application (Korean Patent Application No. 10-2006-77488) which discloses a touch-type character input device wherein manipulation regions arranged on a button means such as a touch screen or a touch pad and associated characters are assigned to the manipulation regions.

[5] However, such a prior application of the present applicant entails a problem in that since it is adapted to be applied to the touch screen or the touch pad, it cannot be used for a cellular phone or other electronic devices which does not include the touch screen or the touch pad, and the touch screen or the touch pad is also high-priced. Disclosure of Invention

Technical Problem

[6] Accordingly, the present invention has been made in an effort to solve the aforementioned problems occurring in the prior art, and it is an object of the present invention to provide a button-type character input device which enables characters to be more expediently input and corrected. [7] Another object of the present invention is to provide a button-type character input device which eliminates the necessity of installing a touch screen or a touch pad to thereby further reduce the manufacturing cost of the character input device.

[8] Still another object of the present invention is to provide a button-type character input device which can modify a character code transmitted to a main unit even without installing a separate character display section. Technical Solution

[9] To accomplish the above objects there is provided a button-type character input device according to claim 1 of the present invention including buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters.

[10] The button-type character input device comprises:

[11] a first region;

[12] a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters;

[13] an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons; and

[14] a character display section for displaying the current character,

[15] wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons;

[16] if an ON/OFF time interval between the second buttons which are depressed and released while the button depressed position is shifted from the currently depressed second button to another second button is within a predetermined time, sequentially designate as a current character, depending on the amount of the shift of the button- depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged; and

[17] if all the second buttons are off and any one of buttons does not become an ON state during the elapse of the predetermined time, transmits a code of the designated current character to a main unit.

[18] To accomplish the above objects, there is provided a button-type character input device according to claim 2 of the present invention including buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters.

[19] The button-type character input device comprises:

[20] a first region; [21] a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters;

[22] a region-rotating section including a button- accommodating portion rotatably mounted thereon for generating a rotation signal in response to rotation of the button- accommodating portion, the button- accommodating portion having the plurality of second buttons integrally accommodated therein;

[23] an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons and the rotation signal generated from the region-rotating section; and

[24] a character display section for displaying the current character,

[25] wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons;

[26] if the rotation signal is generated from the region-rotating section in a state where the second button is in an ON state, sequentially designate as a current character, depending on the amount of rotation of the button-accommodating portion detected by the rotation signal, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged; and

[27] if the second button becomes an OFF state, transmits a code of the designated current character to a main unit.

[28] To accomplish the above objects, there is provided a button-type character input device according to claim 3 of the present invention including buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters.

[29] The button-type character input device comprises:

[30] a first region;

[31] a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; and

[32] an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons, the input-processing section including an input buffer,

[33] wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons and transmits a code of the current character to the min unit; and

[34] transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the second button while sequentially designating as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged.

[35] To accomplish the above objects, there is provided a button-type character input device according to claim 4 of the present invention including buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters.

[36] The button-type character input device comprises:

[37] a first region;

[38] a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters;

[39] a region-rotating section including a button- accommodating portion rotatably mounted thereon for generating a rotation signal in response to rotation of the button- accommodating portion, the button- accommodating portion having the plurality of second buttons integrally accommodated therein; and

[40] an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons and the rotation signal generated from the region-rotating section, the input-processing section including an input buffer,

[41] wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons and transmits a code of the current character to the min unit; and

[42] if the rotation signal is generated from the region-rotating section in a state where the second button is in an ON state, sequentially designate as a current character, depending on the amount of rotation of the button-accommodating portion detected by the rotation signal, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged, at which time transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the second button.

[43] To accomplish the above objects, there is provided a button-type character input device according to claim 5 of the present invention including buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters.

[44] The button-type character input device comprises:

[45] a first region; [46] a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters;

[47] an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons; and

[48] a character display section for displaying the current character,

[49] wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons;

[50] if the button depressed position is shifted from the currently depressed second button to another second button and at least one of the second buttons is maintained in an ON state, sequentially designate as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged; and

[51] if all the second buttons are off, transmits a code of the designated current character to a main unit.

[52] To accomplish the above objects, there is provided a button-type character input device according to claim 6 of the present invention including buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters.

[53] The button-type character input device comprises:

[54] a first region;

[55] a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; and

[56] an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons, the input-processing section including an input buffer,

[57] wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons and transmits a code of the current character to the min unit; and

[58] if the button depressed position is shifted from the currently depressed second button to another second button and at least one of the second buttons is maintained in an ON state, sequentially designate as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged, at which time transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the second button.

[59] In the button-type character input device according to claim 7 reciting any one of claims 1 to 6, a direction key is allocated to the second buttons,

[60] if any one of the second button is depressed and then any one of the second buttons is maintained in an ON state while the button-depressed position is shifted from the depressed second button to a second button adjacent to the depressed second button, or if the second button is depressed and then a rotation signal is generated from the region-rotating section, the input-processing section repeatedly transmits a code of an assigned direction key to the main unit.

[61] To accomplish the above objects, there is also provided a method of inputting characters.

[62] The character input method comprises:

[63] a first step of determining whether an immediately previous character transmitted to a main unit must be corrected;

[64] a fourth step of calculating the position number of a first character constituting the last Hangeul syllable character and the position number of a first character constituting the second to the last Hangeul syllable character in a state where the immediately previous character exits;

[65] a fifth step of calculate the position number of a first character constituting the last

Hangeul syllable character in a state where the immediately previous character is change to the current character;

[66] a sixth step of determining whether or not the position numbers of the first characters constituting the last Hangeul syllable characters are identical to each other in the fourth and fifth steps;

[67] an eighth step of transmitting a code of a back space character to the main unit by the number of times corresponding to the position number of a first character constituting the last Hangeul syllable character in a state where the immediately previous character exits;

[68] a ninth step of transmitting a code of the back space character for deleting the second to the last Hangeul syllable character to the main unit;

[69] a tenth step of sequentially transmitting, to the main unit, codes of characters ranging from the characters constituting the second to the last Hangeul syllable character to the character just before the immediately previous character

[70] an eleventh step of transmitting a code of the back space character to the main unit; and

[71] a twelfth step of transmitting a code of the current character to the main unit.

[72] Preferably, the character input device of claim 8 further comprises a seventh step of determining whether or not the position number of a first character constituting the last Hangeul syllable character is greater than 3 in a state where the immediately previous character exits.

[73] Also, in case of using the character input device of claim 3, the step 1 in the character input method is a step in which if the time t spent for a depressed second button to become an OFF state and then the currently depressed second button to become an ON state prior to the depression of the currently depressed second button is within a predetermined time T, the program proceeds to a next step, whereas if the time t exceeds the predetermined time T, the input-processing section transmits a code of any one of characters assigned to the currently depressed second button to the main unit.

[74] Also, in case of using the character input device of claim 4, the step 1 in the character input method is a step in which if the input-processing section transmits the current character changed in response to the rotation signal generated from the region- rotating section in a state where the second button is depressed, the program proceeds to a next step, whereas if the second button is depressed and then the depression of the second button is released, the input-processing section transmits a code of any one of characters assigned to the depressed second button to the main unit.

[75] Preferably, in addition, in case of using the character input device of claim 6, the step 1 in the character input method is a step in which if the button depressed position is shifted from the currently depressed second button to another second button and at least one of the second buttons is maintained in an ON state, the program proceeds to a next step, whereas if a new second button is depressed and then the depression of the new second button is released in a state where all the second buttons become an OFF state, the input-processing section transmits a code of any one of characters assigned to the newly depressed second button to the main unit.

[76] Also, the character input method further comprises: between the first step and the fourth step,

[77] a second step of determining whether or not an immediately previous character transmitted to the main unit is equal to a back space character; and

[78] a third step of transmitting a code of a character just before the back space character to the main unit if the immediately previous character transmitted to the main unit is equal to the back space character in the second step and allowing the program to proceed to the twelfth step.

[79]

Advantageous Effects

[80] According to the button-type character input device and character input method of the present invention, since the necessity of installing a touch screen or a touch pad is eliminated, the manufacturing cost of the character input device is further reduced as well as characters are more expediently input and corrected. Brief Description of the Drawings

[81] The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:

[82] FIG. 1 is a view illustrating the arrangement of a conventional keypad of a cellular phone according to the prior art;

[83] FIG. 2 is a view illustrating the arrangement of a keypad of a cellular phone according to a first embodiment of the present invention;

[84] FIG. 3 is a view illustrating the arrangement of buttons of a cellular phone according to a first embodiment of the present invention;

[85] FIG. 4 is a flow chart illustrating a character input process according to a second embodiment of the present invention;

[86] FIG. 5 is a view illustrating the arrangement of buttons of a cellular phone according to a third embodiment of the present invention; and

[87] FIG. 6 is a view illustrating the arrangement of buttons of a cellular phone according to a fourth embodiment of the present invention. Mode for the Invention

[88] Reference will now be made in detail to the preferred embodiments of the present invention with reference to the attached drawings.

[89] In this specification, characters refer to consonants such as "D,D, D,..." and vowels such as "D, D, D,..." in "Hangeul", i.e., Korean alphabets, and Hangeul syllable characters refer to Korean characters such as "D, D, ...", etc., as a combination of the consonants and the vowel. Also, in case where consonants and the vowels are separated from a complete Hangeul syllable character so as to be displayed on a main unit, for example, in a state where "DD" is displayed on the main unit, "D" is treated as both a character and a Hangeul syllable character. Of course, it is possible to understand that the characters and the Hangeul syllable characters are commonly used in case where a combination of characters does not form a Hangeul syllable character as in English alphabets (characters) or numerals.

[90] Further, herein, transmission of a code of a character to the main unit means that the character code is transferred to an Input Method Editor (IME), i.e., a character processing section of the main unit so that a desired character is displayed at an input position of a main unit for the character to be input. In case of Hangeul, a character input device receives characters such as consonants and vowels to constitute Hangeul syllable characters to thereby be displayed on a screen. Also, transmission of a character to the main unit means that the character code is transmitted to the main unit as described above, in which the two meanings can be commonly used.

[91] In addition, a button of the present invention refers to an electric switch which generates an ON signal in an ON state during the depression of the button and generates an OFF signal in an OFF state during the release of the depression of the button. Thus, any electric switch capable of generating an ON/OFF signal can be used as the button. Moreover, even in case of a character input device such as a touch pad or a touch screen enabling the entry of a coordinate, as long as the character input device divides a touch region thereof into a number of certain button-shaped sub-regions and serves as an electric switch that determines an ON or OFF state in response to the touching of the divided button-shaped sub-regions, it falls within the scope of a button according to the present invention.

[92]

[93] Embodiment 1:

[94] As shown in FIGs. 2 and 3, in a touch-type character input device according to a first embodiment of the present invention, a part of Korean "Hangeul" characters including consonants and vowels, lower-case English characters, numerals is assigned to a plurality of second buttons, respectively, and the second buttons encircle a first region in such a fashion as to be arranged isolated from each other.

[95] For example, a second button of a numeral "4" is assigned with Hangeul characters

(consonants) "D","D" and "D" and lower-case English characters "g", "h" and "I" besides the numeral "4". The second buttons are arranged such that the second buttons of "0" to "9" and the second buttons of "*" and "#" encircles the first region.

[96] The characters as assigned above are preferably designed such that only a designated character is displayed on a screen when a certain second button is depressed depending on the kind of to-be-input languages such as numerals/English alphabets/ Korean alphabets/special characters/Chinese alphabets/Japanese alphabets, etc.

[97] Each button is an electric switch, so that it generates an ON-signal during the depression of a button while generating an OFF- signal during the release of the depression of the button.

[98] When the second buttons for entering a character are described hereinafter, they are commonly used as "buttons". In case of arranging the buttons on the first region, the buttons are limited to first buttons when describing them.

[99] In the first embodiment, an input-processing section designates as a current character any one of characters assigned to a button which is first depressed among a number of buttons in order to enter a desired character;

[100] if an ON/OFF time interval (hereinafter, the time spent for one button to become an

OFF state and another button to become an ON state by the shift of the button- depressed position is referred to as "time t") between the second buttons which are depressed and released while the button depressed position is shifted from the currently depressed second button to another second button is within a predetermined time (hereinafter, referred to as "time T"), sequentially designate as a current character any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged each time the number of the second buttons depressed by the shift of the button-depressed position reaches a multiple of the designated number; and

[101] if the second button is off in a state where there is no shift of the button-depressed position and any one of buttons does not become an ON state during the elapse of the time T, transmits a code of the designated current character to a main unit.

[102] As an example, a process of inputting a Korean syllable character "D" of "DD" will be described hereinafter.

[103] A user first depresses a button of a numeral "4" assigned with "D". At this time, an input-processing section recognizes "D" as a current character and displays the recognized "D" on a character display section 10. When the user does not release the depression of the button of the numeral "4" but shifts the button-depressed position from the button of the numeral "4" to a button of a numeral "5", the current character is changed into "D". At this time, the button of the numeral "4" and the button of the numeral "5" may be simultaneously depressed depending on the manipulation form of the user and the button of the numeral "5" may become an ON state while the depression of the button of the numeral "4" is released to become an OFF state.

[104] In case where the button of the numeral "4" becomes an OFF state and then the button of the numeral "5" becomes an ON state, if an ON/OFF time interval between the both buttons is within a predetermined time, the input-processing section recognizes it as the manipulation in which the current character is changed into another one of the assigned characters to thereby allow the user to change the current character. Of course, even in case where the button of the numeral "4" and the button of the numeral "5" may be simultaneously depressed, if the input-processing section can allow the current character to be changed into another one of the assigned characters.

[105] Sequentially, if the user shifts the button-depressed position from the button of the numeral "5" to a button of a numeral "6" so as to enter "D", the input-processing section designates "D", i.e., another one of the assigned characters as a current character to display the designated current character "D" on the character display section.

[106] When the current character is designated as a character it is wished to input, the user releases the depression of the button of the numeral "6" to cause the main unit to transmit a code of the current character to thereby complete the input of "D". [107] In the above embodiment, although the shift of the button-depressed position in the order of the numerals "4", "5" and "6" has been described, in case where the button- depressed position is shifted from the button of the numeral "4" to the button of the numeral "5", "D" may be caused to be designated as the current character, and in case where the button-depressed position is shifted from the button of the numeral "4" to the button of the numeral "3", "D" may be caused to be designated as the current character.

[108] As another modification of this embodiment, it will be possible that in a state where the button-depressed position is shifted from the button of the numeral "4" to the button of the numeral "5" or "3", if the depression of the button of the numeral "5" or "3" is maintained for a little while, the input-processing section sequentially designates the characters assigned to the button of the numeral "4" as the current characters at uniform time intervals and transmits a code of the current character to the main unit by releasing the depression of the button of the numeral "5" or "3".

[109] As another modification of this embodiment, it will be possible that when consonants and vowels of Hangeul are all assigned to the button of the numeral "4" and the button of the numeral "4" is depressed, "D" is first caused to appear on the character display section and the current character is caused to be designated in the order of "D","D", "D", "D", "D", "D",... by the elapse of a predetermined time irrespective of the shift of the button-depressed position. Also, when the button-depressed position is shifted in an opposite direction to that in which the button-depressed position is shifted, it will be desirable to change the current characters in the opposite order of the above order in which the current characters are designated. In this case, even when the user mistakenly selects an original button and depresses it, it is possible to correct a character to be input.

[110] As another modification of this embodiment, as shown in FIG. 1, consonants and vowels are assigned to each button, and when the button of the numeral "4" is depressed "D" first appears on the character display section it will be possible to designate the current character in the order of "D", "D", i.e., the characters assigned to a button assigned with the current character and "D", i.e., the character assigned to a button adjacent to a button assigned with the current character by the elapse of a predetermined time irrespective of the shift of the button-depressed position. Subsequently, when the button-depressed position is shifted to allow "D" assigned to the button of the numeral "5" to be designated as a current character, it will be possible to sequentially display any one of "D" and "D" of the button of the numeral "5" as well as "D", "D" and "D" of the button of the numeral "6".

[I l l] The present invention is not limited to the manipulation in which the current character is changed into another one of the assigned characters only when depressing a button just adjacent to the first depressed button, and is intended to change the characters each time the number of the second buttons depressed during the shift of the button-depressed position reaches a multiple of the designated number.

[112] Although the above embodiment has been described the case where the designated number is 1, in case where the designated number is 2, it is possible to shift the button- depressed position from the button of the numeral "5" to the button of the numeral "6" via the button of the numeral "4" to thereby cause "D" to be changed to "D". In case where since there is a high possibility that two buttons will be simultaneously depressed due to the small size of the button is small, the current character can be prevented from being changed continuously.

[113] In addition, after an initially designed number has been set to "2", when the button- depressed position is continuously shifted the designed number can be changed to "1". In this case, it is possible to make the change of the character slow upon the shift of the button-depressed position after an initially depressed operation, and make the change of the character rapid upon a continuous shift of the button-depressed position.

[114] Further, it will be possible to change the designed number depending on the position of the button being depressed. It is possible to make the change of the character slow upon the shift of the button-depressed position between an upper end button and a lower end button, and make the change of the character rapid upon the shift of the button-depressed position between a left side button and a right side button, and vice- versa.

[115] That is, it is possible to allow a designer to optionally control the shift amount of the button-depressed position to check whether the character can be continuously changed when the button-depressed position is shifted to which degree at which position depending on the shift amount of the button-depressed position.

[116] Also, in case where the button of the numeral "4" must be depressed but the button of the numeral "5" is depressed mistakenly, it is possible to change the characters including characters assigned to the buttons of the numerals "4" and "6" just next to the button of the numeral "5" according to the shift of the button-depressed position.

[117] Also, in case where the button-depressed position is mistakenly shifted from the button of the numeral "4" to the button of the numeral "5", it is possible to change the characters including characters assigned to the buttons of the numerals "5" and "7" just next to the button of the numeral "5" according to the shift of the button-depressed position.

[118] In this manner, when "D" is displayed on the character display section, the user releases the depressed of the button. Then, if the time T elapses, the current character, i.e., "D" is transmitted to the main unit. When "D" is displayed at an character input position of the main unit, the user initially depresses a character "D" (Hangeul vowel) assigned to the button of a numeral "1" in the above manner and continuously shifts the button-depressed position to allow "D" of "D,D,D,D,D,D,..." assigned to the button of the numeral "1" to be displayed on the character display section. Then, the user releases the depression of the button of the numeral "1" to allow "D" to be transmitted to the main unit so as to input a desired character.

[119] In addition, the characters "D", "D" and "D" (Hangeul vowels) are caused to be assigned to the button of the numeral "1". When the user initially depresses the button of the numeral "1", "D" (Hangeul vowel) is displayed as a current character on the character display section. Then, the user shifts the button-depressed position from the button of the numeral "1" to another second button so as to select "D". Thereafter, the user shifts the button-depressed position from the other second button to the first button, and then re-shifts the button-depressed position from the first button to the second button to thereby shift the button-depressed position between the second buttons. Then, it is possible to change the characters to "D", "D", "D", "D", etc., i.e., characters of the form such as "D"

[120] In this embodiment, as shown in FIG. 2, there has been described the character display section 10 is provided on a partial area of the screen of the main unit to display a character. FIGs. 2 and 3 show a state in which a cellular phone is used as the main unit and a key input section is used as the character input device. However, it will also be possible to include a separate character display section in the character input device in case of the inventive character input device which is separated from the main unit similarly to as a keypad. Further, the input-processing section can be installed at either the main unit or the character input device irrespective of the installation position, but the input-processing section corresponds to the character input device as long as the input-processing section is associated with the entry of the characters. Thus, the constituent elements of the character input device of the present invention may installed at the main unit, respectively or integrally all together and may consist of a separate character input device.

[121]

[ 122] Embodiment 2 :

[123] As described above and in the first embodiment, in case where the character display section 10 is provided on a separate screen or a partial area of the screen of the main unit, when the user identifies a character designed as a current character is displayed on the screen and then releases the depression of the button, the current character can be transmitted to the main unit. For this reason, there is a little possibility that the characters will be mistakenly entered.

[124] Unlike the first embodiment, in case where the character display section is absent, it will be also possible to display the current character at the character input position of the main unit.

[125] However, in case where the current character is displayed at the character input position on the screen of the main unit, the user recognizes that the current character is mistakenly transmitted to the main unit similarly to the case where the characters are typically input to the cellular phone.

[126] In case of English alphabet, mistaken entry can be solved simply and easily only by depression of a backspace key upon the correction. On the other hand, one Korean syllable character is composed of a combination of the consonants and the vowel as in case of Korean alphabet (Hangeul), such a correction is not easily made.

[127] In case of Hangeul, it will be possible to correct a mistakenly transmitted character, i.e., an erroneously entered character by the following method.

[128] Since Hangeul has characteristics that a leading consonant positioned in front of a vowel becomes a choseong as the initial sound and the vowel becomes a jungseong as the medial sound, the consonant and the vowel constitute any one Hangeul syllable character. In this case, although characters are entered continuously, it is well known that it is possible to softwarely such as IME process a character each consonant and vowel must constitute.

[129] However, the fact that a current character is displayed at the position (hereinafter, referred to as "character input position") where a character will be input on the screen of the main unit means that a code of the current character is already transmitted to the main unit, and as a result the current character is displayed at the character input position. For this reason, the second embodiment differs from the first embodiment in that if a current character is displayed on the character display section and then the displayed current character is the character it is wished to input, the depression of the button of the current character is released to transmit a code of the current character to the main unit.

[130] That is, the second embodiment requires a means for allowing a new current character to be displayed at the character input position while correcting the current character whose code is transmitted to the main unit

[131] This will be described hereinafter.

[132] First, the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among a number of buttons in order to enter a desired character and transmits a code of the designated current character to the main unit so as to allow the designated current character to be displayed at the character input position of the main unit.

[133] If the displayed current character is the character it is wished to input, the user releases the depression of the button. Then, when a predetermined time T elapses, a new character can be input continuously. [134] However, if the button-depressed position is shifted from the first depressed button to another button adjacent to the first depressed button within the predetermined time T, the first depressed button becomes an OFF state and the newly depressed button become an ON state. Subsequently, if the button-depressed position is continuously shifted, the immediately previously depressed button becomes an OFF state and a new button becomes an ON state.

[135] In this case, the input-processing section sequentially designate as a current character any one of the characters including a character assigned to the button on which the current character is arranged or a character assigned to a button adjacent to the button on which the current character is arranged each time the number of the buttons depressed by the shift of the button-depressed position reaches a multiple of the designated number, and transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the button.

[136] This process will be described hereinafter in detail with reference to FIG. 4.

[137] First, at step 1, the input-processing section determines whether to correct a character just before a character is transmitted to the main unit.

[138] In case of using the character input device of the invention of claim 3, at step 1, when a user depresses an arbitrary button, this depressed arbitrary button becomes a current button. Then, if the time t spent for a button depressed prior to the depression of the current button to become an OFF state and then the current button to become an ON state is greater than a predetermined time T, a code of the current character is transmitted to the main unit. If, on the other hand, the time t is smaller than the predetermined T, the program proceeds to a next step 2.

[139] At step 2, the input-processing section determines whether or not the character

(hereinafter, referred to as 'immediately previous character') determined by the button depressed prior to the depression of the current character and transmitted to the main unit is a back space character through an input buffer. If it is determined at step 2 that the immediately previous character is the back space character, the program proceeds to step 3 where the input-processing section transmits a code of a character just before the back space character to the main unit and then proceeds to step 12 where the input- processing section transmits a code of the current character to the main unit.

[140] The process where the program proceeds to steps 2, 3 and 12 will be described with reference to an example of inputting "D".

[141] It can be assumed that although "D" is transmitted to the main unit and the "D" must be transmitted to the main unit, the back space character is first selected to change the character to "D" depending on the arrangement of the characters assigned to a button or the manipulation of the user. [142] In this manner, since the back space character is first selected to cause "D" to be displayed on the screen of the main unit, it is required that "D" as a character prior to the back space character should be first transmitted to the main unit and then "D" should be transmitted to the main unit. Then, a Hangeul syllable character "D" is displayed on the screen of the main unit.

[143] The steps and 2 and 3 are steps where are not needed in case where a character is assigned in order for the back space character not to be changed to the current character when the second button is first depressed or the button-depressed position is shifted.

[144] At step 2, if it is determined that the immediately previous character transmitted to the main unit is not the back space character, the program proceeds to step 4 where the input-processing section calculates the position number of a first character constituting the last Hangeul syllable character and the position number of a first character constituting the second to the last Hangeul syllable character in a state where the immediately previous character exits. Subsequently, the program proceeds to step 5 where the input-processing section calculates the position number of a first character constituting the last syllable Hangeul character in a state where the immediately previous character is changed to the current character.

[145] Next, at step 6, the input-processing section determines the position numbers of the first characters constituting the last Hangeul syllable characters respectively calculated in steps 4 and 5 are identical to each other.

[146] As used herein, the term "position number" refers a cardinal number indicating an order in which an arbitrary character is positioned reversely from the last character of the last Hangeul syllable character displayed on the input window of the main unit.

[147] The process where the program proceeds to the steps 2, 4 and 5 and 6 will be described with reference to an example of inputting "DD".

[148] A user allows the input-processing section to transmit codes of "DD" to the main unit in the order of characters "D", "D", "D" and "D" so as to enter "DD". Then, the user depresses "D" as a Hangeul vowel assigned to the button of a numeral "1" and then shifts the button-depressed position from the button of the numeral "1" to a button adjacent to the numeral "1" button to enter "D".

[149] At this time, since "D" as the Hangeul vowel has been already transmitted to the main unit, it must be changed to "D".

[150] Then, in "DD" in which the immediately previous character exits, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2 and the position number of a first character "D" constituting the second "D" to the last Hangeul syllable character is 5.

[151] In addition, At step 5, assuming "DD" in which the immediately previous character is change to the current character, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2.

[152] In subsequent step 6, the input-processing section determines whether or not the position number of a first character "D" constituting the last Hangeul syllable character "D" in the step 4 is identical to the position number of a first character "D" constituting the last Hangeul syllable character "D" in the step 5. In this case, the position numbers of the first characters constituting the last Hangeul syllable characters in steps 4 and 5 are 2, which are identical to each other.

[153] That is, if it is determined at step 6 that the position numbers of the first characters constituting the last Hangeul syllable characters in steps 4 and 5 are 2 are identical to each other, the program proceeds to step 11 where the input-processing section first transmits a code of the back space character to the main unit to clear "D" as an Hangeul vowel from the main unit and at step 12 transmits a code of "D" as the current character to the main unit to thereby enter "DD".

[154] On the other hand, at step 6, if it is determined that the position numbers of the first characters constituting the last Hangeul syllable characters in steps 4 and 5 are 2 are not identical to each other, the program proceeds to step 7 where the input-processing section determines whether or not the position number of a first character constituting the last Hangeul syllable character is greater than 3 in a state where the immediately previous character exits. An example of the above case will be described hereinafter.

[155] In case where the user desires to input "DDD", it can be assumed that codes of "DD" are first transmitted to the main unit. That is, in this case, a code of a character "D" must be transmitted to the main unit, but a code of a character "D" is previously transmitted to the main unit.

[156] In this case, at step 4, in "DD" in which the immediately previous character exists, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 4 and the position number of a first character "D" constituting the second "D" to the last Hangeul syllable character is 7.

[157] In addition, at step 5, assuming "DDD" in which the immediately previous character is change to the current character, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2 and the position number of a first character "D" constituting the second "D" to the last Hangeul syllable character is 4.

[158] Thus, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 4 at step 4 and the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2 at step 5, so that the program proceeds from step 6 to step 7.

[159] At step 7, in "DD" in which the immediately previous character exists, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 4, which is greater than 3. Accordingly, the program proceeds to step 11 where the input- processing section transmits a code of a back space character for deleting the immediately previous character "D" to the main unit and then at step 12 transmits a code of the current character "D" to the main unit to cause "DDD" to be displayed on the screen of the main unit.

[160] On the other hand, if it is determined at step 7 that the position number of a first character constituting the last Hangeul syllable character is not greater than 3 in a state where the immediately previous character exits, the program proceeds to step 8 where the input-processing section transmits a code of a back space character to the main unit by the number of times corresponding to the position number of a first character constituting the last Hangeul syllable character in a state where the immediately previous character exits. An example of the above case will be described hereinafter.

[161] In case where the user try to input "DD", it can be assumed that "D" must first be input and then "D" must be input, but an immediately previous character "D" is previously transmitted to the main unit to cause "DD" be displayed the screen of on the main unit.

[162] In this case, the immediately previous character "D" must be changed to "D", and this will be described hereinafter with reference to steps 4 to 7 again.

[163] In this case, at step 4, in "DD" in which the immediately previous character exists, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2 and the position number of a first character "D" constituting the second "D" to the last Hangeul syllable character is 5.

[164] In addition, at step 5, assuming "DD" in which the immediately previous character is change to the current character, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2 and the position number of a first character "D" constituting the second "D" to the last Hangeul syllable character is 5.

[165] Thus, the position number of a first character "D" constituting the last Hangeul syllable character "DD" is 2 at step 4 and the position number of a first character "D" constituting the last Hangeul syllable character "D" is 1 at step 5, so that the program proceeds from step 6 to step 7.

[166] At step 7, in "DD" in which the immediately previous character exists, the position number of a first character "D" constituting the last Hangeul syllable character "D" is 2, which is not greater than 3. Accordingly, the program proceeds to step 8.

[167] The above case has been described while including step 7, but although step 7 is omitted, the immediately previous character can be changed to the current character. Also, the use of step 7 enables more rapid change of a character.

[168] At step 8, the input-processing section transmits a code of a back space character to the main unit by the number of times corresponding to the position number "2" of a first character "D" constituting the last Hangeul syllable character "D" in "DD" where the immediately previous character exits. That is, when the input-processing section transmits a code of the back space character once, "D" is cleared, and when the input- processing section transmits a code of the back space character twice, "D" is cleared.

[169] Next, the program proceeds to step 9 where the input-processing section transmits a code of the back space character for deleting the second "D" to the last Hangeul syllable character.

[170] Subsequently, the program proceeds to step 10 where the input-processing section sequentially transmits, to the main unit, codes of characters ranging from the characters "D", "D", "D" constituting the second "D" to the last Hangeul syllable character to the character "D" just before the immediately previous character "D" to cause "D" to be displayed on the screen of the main unit.

[171] Then, the program proceeds to step 12 where the input-processing section transmits a code of the current character "D" to the main unit, "DD" is displayed on the screen of the main unit. Thereafter, the input-processing section transmits a code of a character "D" as a Hangeul vowel to the main unit to thereby enter the Hangeul syllable character "DD".

[172] In the present invention, the transmission by the input-processing section to the main unit of a code of the current character along with a code necessary for returning the operating state of the main unit to an original state prior to the first depression of a button is carried out by the above method.

[173] The above described character input method can be performed by allowing the input-processing section to sense the change of any button along with the time "t" while storing the characters transmitted to the main unit in an input buffer of the input- processing section . In addition, such a character input method is not limited to the use of the character input device of the present invention, but can be used other character input device that changes the current character displayed on the character input position of the main unit while shifting the button-depressed position as well as the touch-type character input device as the prior application of the present invention.

[174]

[175] Embodiment 3 :

[176] In the third embodiment, unlike the change of the current character through the shift of the button-depressed position between the buttons in the previous embodiments, the change of the current character by generation of a rotation signal in response to rotation of a button-accommodating section while depressing a button will be described hereinafter.

[177] As shown in FIG. 5, the button-type character input device according to this embodiment includes buttons for generating an ON/OFF signal so as to input characters to a main unit requiring the input of characters. The button-type character input device comprises: a first button; a plurality of second buttons arranged in such a fashion as to encircle the first button, the second buttons being assigned with a part or all of the characters; a region-rotating section including a button- accommodating portion 20 rotatably mounted thereon for generating a rotation signal in response to rotation of the button-accommodating portion, the button- accommodating portion having the plurality of second buttons integrally accommodated therein; an input- processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons and the rotation signal generated from the region-rotating section. In this case, the input- processing section causes the current character to be changed to another character by sensing of a rotation signal generated from the region-rotating section in response to rotation of a button-accommodating portion in a state where a button is depressed.

[178] The region-rotating section is configured to accommodate buttons on a rotating- region section of a general jog shuttle.

[179] Although a wiring path for transferring the ON/OFF signal generated from the second buttons of such a button- accommodating portion and the rotation signal generated from the region-rotating section to the input-processing section is not described, it will be implemented in a typically well-known various forms.

[180]

[181] Embodiment 4:

[182] In the fourth embodiment, as shown in FIG. 6, the button-type input device further comprises third buttons 30 disposed between the first button and the second buttons, and assigned with a part or all of the characters different from the characters assigned to the second buttons.

[183] The input-processing section designates or changes the characters assigned to the third buttons in the same operating manner as that in the case where the second button is depressed in the second embodiment depending on the depression of the third buttons or the shift of the button-depressed position.

[184] In the fourth embodiment, the button-type character input device includes the first button, the second buttons and the third buttons. In case of the third buttons, a second region-rotating section including a third button-accommodating portion for accommodating the third buttons may be disposed between the first button and the second buttons or at the outside of the second buttons.

[185] Such third buttons will be able to be set as shortcut keys or used as control characters shown in FIG. 6. The use of these control characters enables cellular phones as well as electronic devices such as personal digital assistants (PDAs) to be used more expediently.

[186] [187] Embodiment 5:

[188] In the fifth embodiment, when it is required to change a character input position during the input of characters, the buttons of the character input device function as typical arrow keys, which will be described hereinafter.

[189] In this case, when the first button is depressed and then the button-depressed position is shifted from the first button to the second button within a predetermined time, the input-processing section transmits, to the main unit, a code of a direction key capable of changing the character input position of the main unit along a direction determined depending on the position of the first button and the second button. In case where the input-processing section includes an input buffer, it permits the input buffer to be empty.

[190] For example, in the button arrangement as shown in FIG. 3, when the first button is depressed and then the button-depressed position is shifted from the first button to any one of the buttons of numerals "9", "8" and "0", the input-processing section can transmit a code of a left direction key to the main unit so as to change the character input position.

[191] Also, when any one of the buttons of numerals "9", "8" and "0" is depressed and then the button-depressed position is shifted or the region-rotating section rotates, it will be possible for the input-processing section to repeatedly transmit a code of the left direction key to the main unit.

[192]

[193] Embodiment 6:

[194] In the sixth embodiment, the character input device of the present invention can be used as a means for entry of characters as well as a shortcut key for selecting menus, which will be described hereinafter.

[195] In case of application of the inventive character input device to a cellular phone, a direction key 40 of FIG. 1 may be used as a shortcut key for selecting a specific menu such as text messages, phone numbers, additional services, etc.

[196] For the character input device of the present invention, in case where the main unit is not in a character input state, when the first button is depressed and then the second button is depressed, it is possible for the input-processing section to detect the depression of the first and second buttons and transmit, to the main unit, a code of a shortcut key capable of selecting the specific menu along a direction determined depending on the position of the first button and the second button as described in the fifth embodiment.

[197]

[198] Embodiment 7:

[199] The seventh embodiment is directed to the case where the buttons are densely disposed so that when a button is depressed with a finger of a user, only one button cannot be depressed.

[200] In this case, if it is permitted to designate, as a first depressed button, any one of a middle button, the leftmost button and the rightmost button, the first depressed button can be can be designated.

[201] In addition, even in case where the button-depressed position is shifted, a plurality of buttons is in a state of being depressed simultaneously. Thus, as long as all the buttons don't become an OFF state, the current character can be changed by the shift of the button-depressed position between buttons. That is, although the predetermined time T is not designated, the current character can be changed by the shift of the button-depressed position between buttons until the entire button becomes an OFF state.

[202]

[203] Embodiment 8:

[204] In the eighth embodiment, even in case where the second button is depressed, the button-depressed position is shifted from the second button to the first button and then is re-shifted from the first button to the second button, any one of characters assigned to the first depressed second button can be designated as a current character, which will be described hereinafter.

[205] Although the shift of the button-depressed position between the second buttons has been described, when the button-depressed position is shifted, any one of characters assigned to the first depressed second button is designated as a current character. Thus, the shift of the button-depressed position can be extendedly applied to the first button besides the second buttons.

[206] Therefore, when a user depresses a button assigned with characters "D", "D' and "D" to display a character "D "and then shifts the button-depressed position from the first button to the second button, the characters to be transmitted to the main unit can be designated in the order of "D', "D" and "D".

[207] As mentioned above, the present invention has been described with reference to the various embodiments, but it will be possible to use the button input device of the present invention in combination with a mode of changing a current character to another character assigned to a key by depressing the button several times similarly to buttons of a typical cellular phone.

[208] Further, the present invention can be, of course, applied to any device requiring the input of characters as well as cellular phones.

[209] In addition, the technical spirit of the present invention can be also applied to the case where a touch pad is removed so as to be set as each button, or a button region is displayed on the touch pad in order for the touch pad to be used as a button. That is, the present invention can also be applied to the case where it is possible determine which button is depressed based on a pressure applied or an area depressed while being used as a button irrespective of whether the touch pad is configured of a matrix switch type such as an optical sensor matrix/conductive film type or an analog type such as a conductive film type/pressure sensor type.

[210] Furthermore, among Korean alphabet (Hangeul), English alphabet, numerals, other foreign languages and special characters, the language of the character assigned to the second buttons or the third buttons can be arbitrarily selected to be disposed or altered. Also, the grouping of characters for assignment to each button is merely a matter for a designer to arbitrarily select. It is of course noted that the technical spirit of the present invention is not limited by these matters or to the specific embodiments, but should be construed as the matters disclosed in the appended claims.

[211]

Industrial Applicability

[212] As described above, the present invention can be used in fields it is wished to input using buttons arranged on various electronic devices including cellular phones, PDAs, access security devices, etc., and is configured to easily and simply enter various characters by a limited number of buttons.

[213]

Claims

[1] A button-type character input device including buttons for generating an ON/

OFF signal so as to input characters to a main unit requiring the input of characters, the button-type character input device comprising: a first region; a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons; and a character display section for displaying the current character, wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons; if an ON/OFF time interval between the second buttons which are depressed and released while the button depressed position is shifted from the currently depressed second button to another second button is within a predetermined time, sequentially designate as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged; and if all the second buttons are off and any one of buttons does not become an ON state during the elapse of the predetermined time, transmits a code of the designated current character to a main unit.

[2] A button-type character input device including buttons for generating an ON/

OFF signal so as to input characters to a main unit requiring the input of characters, the button-type character input device comprising: a first region; a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; a region-rotating section including a button-accommodating portion rotatably mounted thereon for generating a rotation signal in response to rotation of the button- accommodating portion, the button-accommodating portion having the plurality of second buttons integrally accommodated therein; an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons and the rotation signal generated from the region-rotating section; and a character display section for displaying the current character, wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons; if the rotation signal is generated from the region-rotating section in a state where the second button is in an ON state, sequentially designate as a current character, depending on the amount of rotation of the button-accommodating portion detected by the rotation signal, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged; and if the second button becomes an OFF state, transmits a code of the designated current character to a main unit.

[3] A button-type character input device including buttons for generating an ON/

OFF signal so as to input characters to a main unit requiring the input of characters, the button-type character input device comprising: a first region; a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; and an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons, the input-processing section including an input buffer, wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons and transmits a code of the current character to the min unit; and transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the second button while sequentially designating as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged.

[4] A button-type character input device including buttons for generating an ON/

OFF signal so as to input characters to a main unit requiring the input of characters, the button-type character input device comprising: a first region; a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; a region-rotating section including a button-accommodating portion rotatably mounted thereon for generating a rotation signal in response to rotation of the button- accommodating portion, the button-accommodating portion having the plurality of second buttons integrally accommodated therein; and an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons and the rotation signal generated from the region-rotating section, the input-processing section including an input buffer, wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons and transmits a code of the current character to the min unit; and if the rotation signal is generated from the region-rotating section in a state where the second button is in an ON state, sequentially designate as a current character, depending on the amount of rotation of the button-accommodating portion detected by the rotation signal, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged, at which time transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the second button.

[5] A button-type character input device including buttons for generating an ON/

OFF signal so as to input characters to a main unit requiring the input of characters, the button-type character input device comprising: a first region; a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons; and a character display section for displaying the current character, wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons; if the button depressed position is shifted from the currently depressed second button to another second button and at least one of the second buttons is maintained in an ON state, sequentially designate as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged; and if all the second buttons are off, transmits a code of the designated current character to a main unit.

[6] A button-type character input device including buttons for generating an ON/

OFF signal so as to input characters to a main unit requiring the input of characters, the button-type character input device comprising: a first region; a plurality of second buttons arranged in such a fashion as to encircle the first region, the second buttons being assigned with a part or all of the characters; and an input-processing section for designating a current character or changing the kind of a character in response to an on/off signal generated from the second buttons, the input-processing section including an input buffer, wherein the input-processing section designates as a current character any one of characters assigned to a button which is first depressed among the second buttons and transmits a code of the current character to the min unit; and if the button depressed position is shifted from the currently depressed second button to another second button and at least one of the second buttons is maintained in an ON state, sequentially designate as a current character, depending on the amount of the shift of the button-depressed position, any one of the characters including characters assigned to the second button on which the current character is arranged or characters assigned to a second button adjacent to the second button on which the current character is arranged, at which time transmits a code of the current character to the main unit along with a code needed for returning the operating state of the main unit to an original state prior to the first depression of the second button.

[7] The button-type character input device according to any one of claims 1 to 6, wherein a direction key is allocated to the second buttons, wherein if any one of the second button is depressed and then any one of the second buttons is maintained in an ON state while the button-depressed position is shifted from the depressed second button to a second button adjacent to the depressed second button, or if the second button is depressed and then a rotation signal is generated from the region-rotating section, the input-processing section repeatedly transmits a code of an assigned direction key to the main unit.

[8] A method of inputting characters, comprising: a first step of determining whether an immediately previous character transmitted to a main unit must be corrected; a fourth step of calculating the position number of a first character constituting the last Hangeul syllable character and the position number of a first character constituting the second to the last Hangeul syllable character in a state where the immediately previous character exits; a fifth step of calculate the position number of a first character constituting the last Hangeul syllable character in a state where the immediately previous character is change to the current character; a sixth step of determining whether or not the position numbers of the first characters constituting the last Hangeul syllable characters are identical to each other in the fourth and fifth steps; an eighth step of transmitting a code of a back space character to the main unit by the number of times corresponding to the position number of a first character constituting the last Hangeul syllable character in a state where the immediately previous character exits; a ninth step of transmitting a code of the back space character for deleting the second to the last Hangeul syllable character to the main unit; a tenth step of sequentially transmitting, to the main unit, codes of characters ranging from the characters constituting the second to the last Hangeul syllable character to the character just before the immediately previous character; an eleventh step of transmitting a code of the back space character to the main unit; a twelfth step of transmitting a code of the current character to the main unit.